ARF868 Radio Modems - User guide version V1.8.1
9
Page
of 26
1.6. Electricity connection
The electrical connection of the modem is via two connectors on the modem bottom plate:
•
Jack type supply connector (on the left of fig.1) with a 2.5mm dia. centre pin.
•
SubD9 type serial data connector (on the right of fig.1).
Specifications of the male plugs to be used:
•
Jack plug (fig. 2) type SWITCHCRAFT 761K for the power supply (available via Adeunis RF)
•
SubD 9 pin connector with lateral locking by two M3 screws (fig. 3)
The jack on the modem plate is also compatible with other types of jack plugs with a 2.5mm central pin, but only specific SwitchCraft 761K
types are lockable with nuts.
1.6.1 Functions of the jack supply connector
Supply to the modem is via the jack plug, at a DC voltage between 4.5V min. and 36V max. The system includes a device against polarity
reversal.
1.6.2 Functions of the SubD9 serial data connector
Pin no
SubD9-Modem – RS232
SubD9-Modem - RS485 (2)
1
2
RXD (Modem Data Out)
TXD/RXD+ (B)
3
TXD (Modem Data In)
TXD/RXD- (A)
4
5
GND
6
Sel RS232
7
RTS (1)
8
CTS (1)
9
Not used
(1) RTS/CTS are only used if the RS232 data rate control is used (See § 4 Configuration).
(2) Half duplex connection only.
1.7. Serial data Bus selection modes
The modem is factory set to RS232 mode (Register S215 at 1).
By reprogramming the register (see § 4 Command mode), it is possible to reposition the modem in the following modes:
•
RS232
•
RS485
•
RS485, Terminal(*) mode
•
Auto-detection
Note : the Auto-detection mode triggers recognition of the equipment connected when switching on, and automatically configures in RS232
or RS485.
(*) The RS485 link needs to be adapted. The modem contains a 120 Ohm resistor (Terminal mode) which needs to be selected (see § 4 Com-
mand mode) if the modem is situated at the end of the RS485 line.
Figure 1
Figure 2
Figure 3
Jack
SubD9
Vcc
Ground
18.6mm